Means for producing teeth on gear-wheels.



C. E. DRUIVHVJOND & C. RIDLEY.

MEANS FOR PRODUCING TEETH 0N GEAR WHEELS.

APPLICATION FILED JULY 25- 1913.

Patented Apr. 13, 1915.

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MEANS FOR PRODUCING TEETH 0N GEAR WHEELS.

APPLICATION FILED JULY 25.1913.

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MEANS FOR PRODUCING TEETH 0N GEAR WHEELS.

APPLICATION FILED JULY 25. 1913.

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MEANS FOR PRODUCING TEETH 0N GEAR WHEELS.

APPLICATION FILED JULY25. I913- ]Patented M12513, 1915.

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JMLVWW EMA CHARLES JEDWA DRUIVIMOND. i

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To all whom it may concern:

Be it known that we, CHARLES EDWARD DeUM oNu and CHARLES Rmnnr, subjects of the King of Great Britain and Ireland, and residing at Daimler Works, Coventry, in the county of Warwick, England, have invented certain new and useful Improved Means for Producing Teeth on Gear-Wheels, of which the following is a specification.

The present invention. relates to the production of teeth on gear wheels and has for its object to form conjugate involute teeth by grinding in an improved manner.

It. has been proposed'to' form involute teeth by grinding, the gear wheel blank being rolled about a cylinder or cone along a plane tangential to. the pitch circle.

The object of the present invention is to produce involute teeth by grinding in' an improved manner, and to provide means by which a greater area of the surface of the grinding wheel may be employed, and also to provide means whereby, by a simple adjustment, gear teeth of difi'erent sizes may be readily ground in one and the same machine.

The invention consists in mounting the grinding wheel in such a manner that it can be traversed to and from the plane along which the gear blank is rolling, whereby the point of the grinding wheel in contact with the blank is moved to and fro in the radial direction, so that a larger area of the surface of the grinding wheel is made operative.

The invention further consists in rolling the blank by means of one or more bands or wires carried by a slide, and in mounting the axis of the blank in a second slide, the two slides being connected by a cross-bar so arranged that the relative amplitude of motion of the two slides can be varied as required to out gear wheels of difl'erent sizes.

The invention further consists in the improved method and means for grinding gear.

wheels with involute teeth hereinafter described.

Referring to the accompanying diagrarntpeciflcationot Letters Patent. Applicatlon filed July at, me. rial No. millet.

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in-g a'larger area of the grinding surface; Fig. 2 1s a diagram of the mechanism for obtaining a rolling motion along various diameters of cylinders without changing the diameter of the rollingcylinder; Fig. 3 is a plan showing the device for truing the face of the grinding wheel; Fig. 4 shows an alternative means for obtaining the relative movement of the gears being ground and the controlling bands; Fig. 5 is an elevation of a machine for grinding bevel wheels; while Fig. 6 is a plan showing a gear blank mounted on a block suitable only for gear of a g ven s1ze.

In the diagram Fig. l, the gear blank is rolled on a plane a b tangential to the base circle, and the grinding wheel 0 is reciprocated with its axis d 6 always parallel to the plane a 6 between the positions shown in full and dotted lines.

One tooth f of the gear wheel being ground'is shown in full lines in the position it occupies when the grinding wheel a is in the position shown in full lines, and the same tooth is shown in dotted lines at g in the position it occupies when the grinding wheel 0 is in the position shown in dotted lines, and it will be seen that by reciprocating the grinding wheel in a direction perpendicular to the rolling plane the whole area between the circles on the grinding surface passing through the points it and is is utilized, while a tooth of true involute form is produced.

The rolling of the gear blank Z is effected by mounting the blank in a suitable bearing' in a slide m which can be traversed in a direction perpendicular to the grinding surface 12. of the grinding wheel 0, which rotates about the axis d e and the turning of the blank about its axis is effected by a steel band or bands 0 passing around and attached to a cylindrical surface ;0 moving with the blank Z and attached at its ends to a slide 9 which is reciprocated in a direction perpendicular tovtte grinding surface it for the purpose of effecting the rolling.

The two slides m and q are connected togather-by a rod r passing through pivoted guides s t carried by the slides m 9 respectively. The rod 7' is capable of movement about a pivot- It carried by a cross slide '21 It will be seen that in this arrangement,

gear wheels of any size within certain limits and any pressure angle can be cut using the same rolling cylinder, and, in cutting spur gearing the side of the tooth will be of correct involute form, the cutting taking place along a line perpendicular to the line of rolling, and in the plane along which the blank is rolled, and it will be seen therefore, that there is no necessity to traverse the work laterally across the grinding wheel, provided a grinding wheel of large enough diameter is used.

The machine may be conveniently arranged as shown in Fig. 3; the grinding wheel 0 rotates about a horizontal axis in bearings in a carriage capable of moving horizontally on slides 2. The gear blank Z rotates in a horizontal plane, being mounted on the spindle of a rolling cylinder p carried by a horizontally moving slide, and

- rotated by a second horizontally moving slide by means of hands, the slides being connected together as shown. in Fig. 2. In order to insure that the grinding face of the wheel 0 is accurate, a diamond or other truing tool a is provided on a carriage 5, adapted to be fixed in a definite position in the machine.

When truing is required the grinding wheel 0 is moved parallel to its axis, until the grinding face is in contact with the diamond which is then traversed across the face.

When the diamond has become worn, the carriage on which it is mounted is moved forward so that the acting face of the diamond comes against a fixed stop 6, so that the diamond or like truin device forms a fixed point of reference in t e machine.

In the modified form of gear motion shown in Fig. 4 the pivot for the rolling cylinder 11 and arbor for gear 12 to be ground is mounted on the slide 13.

A reciprocating motion is given slide 13 by means of screw 14; this motion rolls the cylinder along the steel bands 15, as al ready described.

The feed screw 14 carries a pinion (or a rolling cylinder connected to steel bands may displace the rack and pinion) which engages with a rack carried on slide 16. The movement of slide 13 by screw 14 also gives motion to slide 16, at right angles to 13.

On slide 16 is pivoted a slide 17 which may be set at any desired angle, and which operates through a slide block carried by slide 18. When this slide 17 is set at zero or at right angles to slide 13, the movement of slide 13 imparts nomotion to slide 18, and this would be the correct setting for any gear having a base circle same diameter as rolling cylinder-for any gear greater or less in diameter, the slide 17 would be set to angle required either to right or reduced roll to the gear by the movement of slide 18.

The two slides'16 and 18 may also be operated by means of screws as shown for 13, the two screws being geared together by a set of change gears, which would give a ratio of movement required for any diameter of gear being treatedthese gears would take the place of pinion, rack andslide 16 and 17 no gears being used when base circle of gears equals rolling cylinder diameter.

Further, it will be seen that the same method may be applied to the cutting of bevel gear by rolling the blank on a cone instead of a cylinder as above described, the correct involute bevel teeth being thus obtained. Apparatus suitable for carrying this out is shown at Fig. 5. The gear blank 1 is rolled on a cone about the axes 2, 3, by means of bands 4 carried by the slide 5, moved longitudinally by a screw 20, the grinding wheel 6 being mounted with its axis horizontal. The rolling cone can be swung about an axis 7 to suit diiferent sizes of gear, and change speed gears 8, connecting the pinion 21 with the screw 20 are provided to give the correct rolling motion to the permanent rolling cone, to suit the particular gear which is being ground. The

gear quadrant 9 driven by the pinion 21 carries the work head and arbor 10.

If desired, instead of using slides connected so that their relative movement may be altered, an arrangement as shown in Fig. 6 may be used, separate blocks 12 being provided, so that the gear blank is rolled upon a block having a rolling circle of suitable diameter for the size of gear required.

Having now described our invention what we claim as new and desire to secure by Letters Patent is 1. Means for generating inv'olute teeth by rolling on a base circle, comprising in combination a grinding wheel, a blank carrying slide, a shaft carried by said slide, a rolling drum on said shaft, means for carrying said blank on said shaft, means for oscillating said drum on said shaft, means for traversing said grinding wheel to and from the plane of rolling of said drum, whereby the circular line of contact of the grinding wheel with the blank is moved to and fro in a radial direction, as set forth.

2. Means for generating involute teeth by rolling on a base circle, comprising in combination, a grinding wheel, a blank carrying slide, a shaft carried by said slide, a rolling drum on said shaft, means for carrying said blank on said shaft, a sec slide, bands attached to said second slide to said rolling drum, a pivoted cross adapted to connect said slides, the pivot of a said bar being adjustable, as and for purpose described.

In testimony whereof We have signed 0nd names to this specification in the presence of and two subscribing Witnesses. bar CHARLES EDWARD DRUMMOND.

CHARLES RIDLEY. he Witnesses W. F. VAUGHAN, our C. WEBBER. r 

